Organ or tissue transplantation is an effective treatment of many conditions associated with organ failure. The transplantation of donor's organ or tissue must be accompanied by chronic, systemic suppression of the recipient's immune system in order to avoid graft rejection.
The graft endothelial cells are known to play a critical role as initiators, participants and targets of both acute cellular rejection and antibody-mediated allograft rejection.
It is also known that transplantation of avascular embryonic tissues to replace the function of diseased organs offers several advantages relative to transplantation of fully differentiated adult organs: such avascular tissues are less immunogenic, and are less susceptible to humoral rejection than are adult organs (e.g. see WO2006077592).
Blood vessels of various species that were subjected to treatment destroying their entire cellular components but leaving intact the extracellular matrix (decellularization) and that were repopulated with cells have been investigated for their utility as scaffolds for vascular tissue engineering. Decellularized human umbilical veins (HUVs) have been suggested as scaffolds for vascular tissue engineering (Daniel et al.), whereas
WO95/31944 discloses a method for treating grafts and rendering them nonthrombogenic and substantially non immunogenic by coating their inner lining with extracellular matrix (ECM).